package com.swn.common.util;

import java.security.Key;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;

import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;
/**
 * DES加密算法工具类
 */
public class DESUtils {
private static Key key;
    private static String KEY_STR = "!@#$%^&*";// 密钥
    private static String CHARSETNAME = "UTF-8";// 编码
    private static String ALGORITHM = "DES";// 加密类型
    
    
 
    static {
        try {
            KeyGenerator generator = KeyGenerator.getInstance(ALGORITHM);
            generator.init(new SecureRandom(KEY_STR.getBytes()));
            key = generator.generateKey();
            generator = null;
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }
    
    
    private Key initKeyForAES(String key) throws NoSuchAlgorithmException {
        if (null == key || key.length() == 0) {
            throw new NullPointerException("key not is null");
        }
        SecretKeySpec key2 = null;
        SecureRandom random = SecureRandom.getInstance("SHA1PRNG");
        random.setSeed(key.getBytes());
        try {
            KeyGenerator kgen = KeyGenerator.getInstance("AES");
            kgen.init(128, random);
            SecretKey secretKey = kgen.generateKey();
            byte[] enCodeFormat = secretKey.getEncoded();
            key2 = new SecretKeySpec(enCodeFormat, "AES");
        } catch (NoSuchAlgorithmException ex) {
            throw new NoSuchAlgorithmException();
        }
        return key2;

    }
 
    /**
     * 对str进行DES加密
     * 
     * @param str
     * @return
     */
    public static String getEncryptString(String str) {
        BASE64Encoder base64encoder = new BASE64Encoder();
        try {
            byte[] bytes = str.getBytes(CHARSETNAME);
            Cipher cipher = Cipher.getInstance(ALGORITHM);
            cipher.init(Cipher.ENCRYPT_MODE, key);
            byte[] doFinal = cipher.doFinal(bytes);
            return base64encoder.encode(doFinal);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }
 
    /**
     * 对str进行DES解密
     * 
     * @param str
     * @return
     */
    public static String getDecryptString(String str) {
        BASE64Decoder base64decoder = new BASE64Decoder();
        try {
            byte[] bytes = base64decoder.decodeBuffer(str);
            Cipher cipher = Cipher.getInstance(ALGORITHM);
            cipher.init(Cipher.DECRYPT_MODE, key);
            byte[] doFinal = cipher.doFinal(bytes);
            return new String(doFinal, CHARSETNAME);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }
    
    public static void main(String[] args) {
    	String s = getEncryptString("socialorg");
    	System.out.println(s);
    	System.out.println(getDecryptString(s));
	}
}